1. Field of the Invention
The present invention relates to the field of internal combustion engines and in particular to oscillating types for vehicular application.
2. Description of related art
The most popular internal combustion engine for vehicular application, the piston-cylinder type, is inefficient for three reasons. First is that it is necessary to throw away about one third of the heat of combustion in order to keep the cylinder head, valves and springs at desirable operating temperature. Otherwise, the engine becomes inoperative when the valve springs set and relaxate, or the cylinder head breaks when the valves expand in their seats. Moreover, severe thermal distortion between the cool parts around the air intake valves and the hot parts around the exhaust discharge valves due to high operating temperature increases the risk of breaking the cylinder head. Second is that much mechanical power dissipates back into unbenificial heat on account of excessive friction between rubbing parts. Third is that there is always incomplete combustion of fuel because exhaust is not totally discharged from the combustion chamber during the exhaust stroke in the four stroke engine and scavenging in the two stroke engine. The carbon dioxide and water vapor remaining inside the combustion chamber during the intake stroke are not capable of oxidizing fuel mixing with them. Moreover they decrease the air capacity of the engine. The result is incomplete combustion and presence of unburnt fuel and carbon monoxide in the exhaust.
The piston-cylinder reciprocating internal combustion engine has a heavy weight to output power ratio because of extra weights contributed by water and metal parts of the cooling system as well as there is only half to one power cycle per working chamber for every shaft rotation or two strokes.
In spite of its inefficiency and heavy weight to power ratio, the piston-cylinder reciprocating internal combustion engine is still the most popular and developed reciprocating internal combustion engine due to its general economy and satisfaction of its users.